An electromagnetic switching device of the generic type is described in German Patent No. 37 13 412 A1. The contact bridge carrier is actuated here using a toggle by a contactor magnet arranged laterally offset with respect to the contact bridge carrier. The electromagnetic contactor drive and the instantaneous release are arranged parallel to one another on both sides of the longitudinal central axis of the contact bridge carrier. The contact springs which effect the contact pressure are supported against the housing base. A high short-circuit breaking capacity is achieved by providing extinction chambers of appropriately generous dimensions which are situated in the lower part of the housing, which is provided for mounting. However, this design entails a relatively large overall volume. The contactor magnet is fastened with its movable part to a yoke which is guided displaceably and from which a plunger projects in the direction of actuation of the contactor magnet against an operating rocker via which the contact bridge carrier can be actuated. Coupling the contactor magnet to the contact bridge carrier is therefore relatively complicated. The elements for transmitting force which are required for this purpose are exposed frequently to stresses in accordance with the switching rate, and can increase the risk of failure of the switch.
The electric switch described in German Patent No. 41 04 533 C2 is likewise of the generic type. The latter essentially comprises an arc housing and an operating or actuating mechanism housing coupled to the latter, in which the electromagnet and the instantaneous release are arranged parallel to one another. The instantaneous release is arranged in the middle relative to the contact bridge carrier, i.e. the longitudinal centre line of its striker pin for actuating the contact system is aligned with that of the contact bridge carrier. The electromagnet essentially comprises a fixed iron core, a movable iron core and a coil. Fastened to the movable iron core is a transmission component which, upon movement of the movable iron core, i.e. upon the application of current to the coil, presses on a beam which can pivot about a fixed axis of rotation and thereby releases the contact bridge carrier and effects the contact closure. Thus, the actuation of the contact bridge carrier by the electromagnet is not performed directly, but via various linkages or intermediate elements. Furthermore, the parallel arrangement of the release and of the electromagnet with respect to one another produces a relatively large overall volume.